Time control mechanism



Jan. 18, 1938. l.. J. GRIFFEY ET A1.

TIME CONTROL MECHANISM Filed Jan. 15, 1936 3 She'etS-Sheet l mon/bons Jan. 18, 1938. L. '.l. GRIFFEY ET AL TIME CONTROL MECHAN I SM Filed Jan.y 13, 1936 :s sheets-sheet 2 LMI-Gr@ Jan. 18, 1938.

L. J. GRIFFEY ET AL TIME CONTROL MECHANISM Filed Jan. 13, 1936 5 Sheets-Sheet 5 ML, l +I w Patented Jan. i8, i938 greater v W s V El c' q fyi 'l Easj ..1 testte TINIE CNTROL E/iiECHANS-WI Leon i. Griffey and Chester C. Herndon, Tulsa, Okla., assignors to Harden-Waters, Inc., Tulsa,

kla.

Application January 13, 1936, Serial No. 58,943

l Claims.

Our invention consists in new and useful improvements in pneumatic time control inechanism and has for its object to provide a timing device for use in connection with the periodic 5 operation of valves or the like, which is positive and powerful in action, flexible as to adjustment and relatively simple in principle and operation.

Although adaptable to many uses, as will be covious roni the following description, our invention is primarily designed for use in connection with a pilot valve mechanism for controlling one or more motor valves in an assembly such for example as that shown and described in the copending application oi Leon J. Griiicy, Serial No. 8,359, viatented July 2l, i936, No. 2,048,607.

Heretoiore, various forins of time control mechanisrn have been employed for periodically operating valves, switches or the like, wherein conventional spring clocks, electric clocks or tur. ines have been employed as the controlling mecha nism. However, with manually wound clock mechanisms, constant supervision and periodic winding by the operator have been necessary, and in many instances, electric power for operating an electric clock has not been available at the points of installation. Furthermore, in mechanisms employing a turbine as the operating medium, a change in operating pressure changes the timing of the clock, whereas with the power unit designed by us, the timing device is capable of operation with no error in time and with a wide range of pressure change. y

t is the primary object of our invention to overcome the disadvantages inadequacies of 35 devices heretofore employed and to this end we have provided e. pres. .1re actuated diaphragm power unit which serves the driving means for the time controlled pilot valve operating mechants. and at the time winds the roan spring of the clock rn chanisrn and maintains the in constant operating condition.

A further object of our invention is to provid means for controlling and adjusting the opera- 45 tion of the pilot valve actuating mechanism for any combination of movement and idleness. That is, the device may be so adjusted as to be capable of constant movement, to any iizted time ci movement, once for example in every twenty-four hours, remaining idle for the remainder of said twenty-four hours.

With the above and other objects view inch will appear as the description proceeds, our invention consists in the novel features herein set forth, illustrated in the accompanying (Cl. ll-J7) the appended claims.

Referring to the drawings in which numerals of like character designate similar parts throughout the several views,

Fig. l is a View in rear elevation partly in section, showing the power unit and time control mechanism.

2 is an enlarged sectional detail ci a portion of Fig. l.

Fig. 3 is a view in iront elevation partly broken away to illustrate the stop adjustment and actuating means for the valve controlling disc.

Fig. ll is a sectional view taken on line l-i ci Fig. l showing the power unit, time control niech anism and the disc stop adjustment.

Fig. 5 is an enlarged detail oi the lever .tor periodically operating the diaphragm valve.

Fig. 6 is an enlarged sectional detail of the main spring winding yoke.

Fig. 'i is a perspective view or" the same.

Fig. 3 is a detail perspective of the pilot valve operating lever, and

Fig. 9 is a detail perspective ci the combined stop and pawl member employed in connection with the disc operating mechanism shown in Fig. 3.

In the drawings, l represents a base member which is preferably composed oi suitable cast metal and is provided with a plurality of longitudinally extending fluid passageways and a pilot valve shown in dotted lines in Fig. 3 and similar to the arrangement shown in said co-pending application now Patent No. 2,048,597. A pipe 2 leads from a source of operating pressure fluid and Y. terminates in communication with a conventional pressure reducing valve 3, one outlet of which is connected by an l. l and short pipe t to the inlet passageway in the body member l. A pilot valve connected to stem (see Figs. 3 and e) controls the passage of uid from the inlet passageway to a plurality of discharge passageways, the outlet ends of which are shown as closed by plugs 'i and l but which when assembled are connected into conduits leading to respective motor valve diaphragrns. The foregoing is more fully described in said co-pending application but is briefly referred to herein to present a more complete picture of the entire assembly forming the subject matter ci the present invention.

The opposite outlet of the pressure reducing valve It is connected into a T il, one end oi' which is provided with a pop valve it, its other end dis:- charging through a line i i into the inlet end of a diaphragm chamber i2. The inlet end of the diaphragm chamber forms a housing I3 for a suitable valve it having an upwardly projecting stem l5 (Fig. l), said valve being normally held by spring means in closed position. A diaphragm i5 extends across the diaphragm chamber and is secured in place by any conventional means between the flanges of the chamber l2.

The upper end of the diaphragm chamber i2 is provided with an internallythreaded boss I9 adapted to receive an adjustable diaphragm stop sleeve 'it which extends downwardly a predetermined ldistance in the upper half of the diaphragm chamber for the purpose hereinafter set forth. The sleeve 2li is internally threaded to receive the lower end of a tubular distance piece 2i, the upper end of which terminates within a housing 22 for the time control mechanism as shown in Fig. 1. The weight of the diaphragm chamber is supported by this distance piece 2! and is prevented from turning on the latter after adjustment, by means of a suitable bracket ll' fastened to the main housing IS carrie-d by the base member l.

At the central portion of the diap-hragm I6 we secure the lower end of an upwardly extending sleeve t which projects through the` bore of the dista-nce piece El in slidingr engagement with the upper end thereof. The upper end of the sleeve 2S terminates in a cylindrical rack Eil which is movable up and down with said sleeve in response to the movement of the diaphragm l, the teeth of said rack meshing with the teeth of a gear 25 hereinafter referred to more in detail.

Extending through the center of sleeve 23 is a valve operating plunger 2li, the lower end of which projects through the diaphragm l?) and terminates in an enlarged head 2l immediately in line with the valve stem lb, its upper end extending beyond the terminus of said sleeve a predetermined distance for engagement by a pivoted lever 28, the operation of which is eiected by the time control mechanism as will hereinafter appear. A bushing 23 at the lower end of the sleeve 23 slidably engages the lower end of the plunger 26 (see Fig. 2), and a similar busliing 3Q at the upper end of said sleeve slidably guides the corresponding end of said plunger. Suilcient clearance is provided between the lower bushing 29 and the plunger 25 to permit the escape of pressure fluid, and said sleeve is provided With a small port 3l above the bushing which discharges pressure iluid :from the interior of the sleeve into the upper half or" the diaphragm chamber E2 from whence it bleeds to atmosphere through a port 3?. in the wall of the upper diaphragm casing. The sleeve 23 and diaphragm l@ are normally maintained in the position shown in Fig. l by the downward pressure of a coil spring 33 located in the enlarged lower portion of the distan-oe piece l said spring abutting an adapter 315 on the upper face of the diaphragm it. f

Returning to the gear 25, it will be seen from Tlg. l that when the sleeve 23 and the rack 211- carried thereby are moved upwardly by pressure under the diaphragm It, said gear 25 is rotate-d in clockwise direction. This .gear is xed on a shaft 35 which also carries a crank arm 36, the outer end of which rides within a yoke 37. This yoke is preferably of an inverted U-shape in cross section, its side walls being provided with longitudinally extending slots 33 adapted to receive the. projecting ends of a pin 3s extending transversely through the end of crank arm 36. Details of this yoke arrangement are shown in Figs. 6 and 'l of the drawings. One side wall of the yoke 3T is extended longitudinally to form an arm lill, the end of which is fastened to a coil spring il Xed as at l2 to a suitable point on the rear clock plate U32 (Fig. 4), said spring normally tending to draw the yoke 3l toward the right, looking at Fig. l. The forward end of the top portion of the yoke 3l is bent downwardly at an angle as at 43 to forni a pawl member for engagement with the teeth of a ratchet lll mounted on a shaft 25 and freely rotatable thereon directly in front of the arm lil and in line with the yoke 37.

@6 represents the main spring of the time control mechanism which surrounds the shaft 45 as shown in Fig. 4, being secured at one end to the ratchet Il and at its other end to a timing gear i7 fixed to the shaft 45. The shaft 45 is geared to a balance wheel 48 in the conventional manner (not shown) which regulates the speed of rotation of said shaft at exactly one revolution per hour by means of a hair spring 49 and hair spring adjustment lever 5l). A stem and knob 48 project through the rear o the clock housing, said stem being operatively connected to the balance wheel 43 for starting purposes as will hereinafter appear.

The timing gear d? is provided with sixty teeth, and as it is fixed to the shalt 55, rotates at a speed or' revolution per hour or a distance of one tooth per minute. The lever 28 heretofore referred to is pivotally mounted on a shaft 5E (Fig. i) and is provided adjacent the periphery of the gear il with an abutment 52, and at its other end with a right angular hori- Zontal projection shown in detail in Fig. 5, which lies immediately above the upper extremiity of the valve plunger 2li and is normally engaged thereby, with the abutment 52 riding in the notches of the respective teeth of the timing gear il. Thus, the operation of the main spring and clock mechanism rotates the timing gear 4l at the rate o1" one revolution per hour as before stated, which causes one tooth per minute to engage the inclined face of the abutment i2 and rocks the lever 28 on the shaft 5I in counterclockwise direction., looking at Fig. 1. This movement depresses the plunger 25 by means of thc projection and in turn thc valve stein l5 of valve lll to be depressed, opening the valve and permitting pressure huid from line H to enter thc pressure chamber under the diaphragm it. The pressure under diaphragm forces the same upwardly and with it the sleeve i which, through the medium of the cylindrical rack 2d, rotates the gear and shaft 35 in clockwise direction. The upward movement of the diaphragm l and parts connected thereto is controlled by the adjustable stop sleeve 20. The crank arm xed to the shaft 35 is correspondingly, rotated in clockwise direction together with the pin 3S, thus relieving the tension on the spring li attached to the yoke 3l and permitting said spring through arm 4B to pull the yoke to the right in Fig. l.

During this movement ol the yoke, the pawl member i3 at the forward end of the yoke engages an adjacent tooth on ratchet lili and rotates the same in clockwise direction. This ratchet "lll being freely rotatable on shaft 45 and Xed to the main spring 4G, Winds said main spring until such movement is stopped by the arm l5 reaching the end of its travel. This winding will take place upon each movement of the crank arm 3G by the rack 213 and sleeve 23 until the resistance of the main spring iii is equal to the tension of spring Gl, after which the pin 39 will move freely in slot 38 with no further Winding of the main spring 98. A snap pawl t pivotally mounted as at 55 is normally held in engagement with the teeth on the ratchet 44 by means of a spring 56 and maintains the wind of the main spring t6 by preventing the ratchet i4 from rotating in a reverse direction.

Turning. to 3 and e. it will be seen that the shaft 35 which carries the pinion 25 is elongated and extends forwardly through the wall of the main housing i8 and terminates in the front thereof where it carries a crank 5l held in place by a set screw 58, the upper end of said crank being bent at right angles to form an abutment 59 (see Fig. 4). On the same shaft 35 adjacent the crank arm 5l, an upwardly projecting lever 88 is freely mounted, the upper end o-f said lever carrying a pivoted actuating channel 5l (see Figs. 3 and 9). The forward end of the channel 6i is closed as at 82 to form a pawl which is normally held in engagement with the teeth of a ratchet 53 by means of a spring 84. The ratchet 83 is fixed to a coi-axial gear 65 which in turn meshes with a large gear 66 nxed on a hub (il hereinafter referred to more in detail.

A rating screw 68 suitably mounted in a tapped post 69 provided with a lock nut 10 limits the pick-up of ratchet teeth on ratchet 63 by the actuating channel 6|. In other words, by adjusting the position of the rating screw 68 in the post 89 so as to move its inner end either to the right or to the left, varies the position of the actuating channel 8l with respect to the ratchet 63. The spring 64 serves the dual purpose of maintaining the pawl end of the actuating channel 6l in engagement with the periphery of the ratchet 63 and normally tends to pull the actuating channel and lever 80 in a clockwise direction into engagement with the yend of the rating screw 68 to pick up a predetermined number of teeth on the ratchet 63. Thus, by varying the position of the rating screw 68, the number of teeth picked up may be correspondingly varied from one to six teeth.

The upward movement of the rack 24 which causes the vrotation of the pinion 25 in a count-erclockwise direction, looking at Fig. 3, correspondingly rotates the crank 5'! which, by means of the angular abutment 59, engages the adjacent edge of lever 60. This pulls the actuating channel Si away from the end of the rating screw 68 against the tension of the spring 84, its pawl end 82 engaging the teeth of the ratchet 83 and rotating the latter in a counter-clockwise direction. Gear 85 xed to the ratchet E3 and rotated thereby causes the clockwise rotation of the large gear 68 a predetermined extent dependent upon the setting of the rating screw. The ratchet 83 is prevented from rotating in a reverse direction by a snap pawl 'H pivotally mounted at 'l2 and normally held in engagement with the periphery of the ratchet by a spring 1S.

The hub 6l carrying the gear E8 rotates on a shaft 'I9 fastened to the clockcase i8 by a nut l5 and is held in place on this shaft by a shoulder' screw 18. On this same hub El, we provide 'a time controlled disc 'Il which is secured in place by a knurled nut i8, the latter being locked to the disc by set screws 'i9 as shown in Fig. 3. Thus, the hub 61, gear 86 and disc 'l1 are held as a unit and the time controlled disc Tl rotates at a speed proportionate to the speed of rotation of the ratchet gear 63.

Referring to Fig. 3, the disc ll is provided with three coaxial annular rows of apertures 80, 8l and 82 adapted to receive screw threaded pins 83 which', as in the similar disc in the aforementioned co-pending application, are provided with knurled heads at their outer ends and project laterally through the inner face of the disc as shown in Fig. 4, to engage the operating lever 84 of the pilot valve 6.

This operating lever 84, as shown in detail in Fig. 8 and assembled in Fig. 3, comprises a substantially straight horizontally extending arm. 85 carrying a pin-engaging arm 88 which is secured thereto in spaced relation by suitable rivets 81, 88 and 89, the pin-engaging end of arm 88 is Off-set as at 99 and provided with an abutment having opposed cam surfaces 9| and 92 which terminate in a common slot 93 for the purpose hereinafter set forth. The opposite end of the pin-engaging arm 86 is off-set to a greater extent as at 94 to form a pivotal bearing 95 which cooperates with a corresponding bearing 98 formed in the adjacent end of the arm 85. The off-set portion 94 is retained in spaced relation from the adjacent end of the arm 85 by a spacer Si which is held in place by the rivet 89.

This mechanism just described is pivotally mounted as at 98 on a suitable fulcrum secured to the wall of the casing i8 as shown in Fig. 3, with the pin-engaging abutments 9| and 92 lying immediately behind but slightly spaced from the disc il and in line for engagement with the inner projecting ends of pins 83 in the apertures in said disc.

At an intermediate point, the pin-engaging arm 86 carries a valve engaging L 99 which is pivotally supported by the rivet 88, its foot extending forwardly and being provided with a threaded aperture mii. The upper end of the pilot valve 8 is threaded as shown in Figs. 3 and 4 to engage the aperture in the foot of the L 99, suitable adjusting nuts lill being provided to vary the operating position of the valve.

The opposite end of the horizontal lever 85 is provided with a series of vertically spaced apertures 92 adapted to co-operate with a raised button of conventional design on the arm |03 adjustably mounted at 48d on the wall of the casing i8. The arm 85 being resilient, its varying positions are retained until positively changed by means of this button and aperture arrangement.

Thus, as the disc il is rotated in clockwise direction by the mechanism hereinbefore described, the projecting inner ends of the pins 83 arranged at predetermined positions in the apertures 88, 8l and 82 successively engage the respective cam surfaces 9i and 92 to positively move the arm 84 up or down. This movement is transmitted by means of the L. 99 to the pilot valve 9 in a manner similar to that described in connection with the aforesaid co-pending application Serial No. 8,359. As the engaging pin reaches the end of the cam surface, it passes freely through the slot 93 and continues in its path, the arm assembly 84 being retained in its assumed position until positively changedby the engagement of a subsequent pin 83 with the abutment of the pin-engaging arm 88.

In some instances it is desirable and necessary to provide for a control which will operate the disc 'il through any desired span of time and then entirely stop the operation of said disc for a desired period before resuming its rotation. In

combination of movement and idleness from constant movementl to any IiXed time of movement, one every twenty-four hours.

To this end we provide a pinion |05 which is keyed to and rotates with the main spring shaft 45 at a constant speed of one revolution per hour. This pinion meshes with a gear |05 on a shaft which carries a second pinion lill (see Fig. 1), which latter pinion rotates at the same speed with gear |06 and meshes with a gear |08 on an enlarged shaft |09 as shown in Fig. 4. The reduction of speed through this train of gears gives a resultant rotation to shaft |09 of one revolution per day.

As shown in Fig. 3, a stop disc HG on the front side of the housing i8 and behind the timing disc 'il is held in place on the forward end of the shaft lil@ kby means of a suitable lock screw lll, said disc. Il@ being drilled with twenty-four tapped holes |52 arranged in an annular row near the periphery and adapted to receive stop pins l i3. As in the case of the timing disc, these. pins are provided with knurled heads and are screw-threaded for engagement with the holes H2, their inner ends projecting through the disc as shown in Fig. 4.

The lower end of the lever 6l) with operates the actuating channel 6| is extended downwardly `and suitably oil-set to form a foot H4 (see Fig.

9), which lies in a plane between the disc I| and the ratchet in line for engagement with any one of a series of pins inserted in said disc. This foot is so designed that when it contacts one of the pins H3 in the twenty-four hour discV ll, the entire pick-up mechanism including the gear actuating assembly lever t@ will be held in its extreme coLmter-clocirwise position out of contact with the actuating crank 5l on the shaft 35. Thus, as long as the foot |54 at the lower end of the actuating lever Si) is in contact with a pin l I3 in the twenty-four hour disc lill, all rotation of the timing disc 'il will cease. The power unit on the opposite side of the casing lll will continue to operate but its only function will be to keepl the clock mechanism Wound and maintain the tim.- ing of the entire unit.

The front face of the casing I8 may be closed by any suitable means such as by the hinged door ld, and the rear face of the clock housing 22 may be closed by a plate 22a seciued in place b-y suitable screws or the like. The entire assembly may be supported upon a vertical standard la or any other suitable means.

In operation, there is a constant source of gas pressure available through line H from the gas f line 2, and in order to start the mechanism, the

operator depresses the extension 53 on the lever 28 which in turn forces the plunger 26 downwardly to open the valve'l, permitting pressure to enter under the diaphragm i6. At the same time, he starts the balance wheel 48 into motion by turning the knob 48. The pressure under the diaphragm force-s the same upwardly and with it the sleeve 23 and rack 2li to rotate the gear 25 as hereinbeiore described. The' valve I5 then closes and the pressure iiuid under the diaphragm escapes through the clearance between the plunger 25 and the bushing 29 in the sleeve 23 and is discharged through ports 3| and 32 to atmosphere.

The rotation of gear 25 in this manner has a two-fold function. It winds the main spring oi `the clock through the medium of the channel assembly 3l and spring 4l, and at the same time operates the timing disc Tl through the medium of the lever 6B, channel Si and gearing assembly connected with the ratchet G3.

Thus, through the mechanism timed in operation by the clock structure, the plunger 2B is depressed once every minute which in turn winds the clock main spring and rotates the timing disc ll to an extent dependent upon the adjustment of the rating screw 68. In other words, if this rating screw is set so that the channel 6| engages only one tooth on the ratchet t3, the extent cf rotation of the disc l'l through the train of gearing hereinbefcre described will be a minimum, While if said rating screw is adjusted to permit a piel; up of six teeth on the ratchet G3, the extent of rotation of the disc 'il will be proportionately increased. Ihe gearing between the ratchet @3 and the timing disc ll' is such that with a ene-tooth pick up per minute on` the ratchet, the timing disc will rotate at the rate of one revolution every six hours. On the other hand, with the maximum pick up of six teeth per minute, the timing disc will rotate at the rate of one revolution per hour. As the disc 'il' is actuated only at one minute intervals, the minimum` selectivity of valve action remains at one minute intervals regardless of the speed ci disc rotation. The object of the variable speeds of rotation of the disc is of course to change the time sequences of valve action to more efiiciently determine the -time cycles desired.

When it is desired to so control the mechanism that during' certain predetermined periods the timing disc 'il will remain completely idle without effecting any operation of the pilot valve 6, the pins H3 are so arranged in the apertures in the twenty-four hour disc i lll that at the desired time, one of the pins will come in line for engagement by the foot lili at the end of the lever 6D. As before described, as long as a pin lies in the path of this foot H4, the timing disc operating mechanism remains idle as the channel assembly 6| is maintained in its extreme counter-clockwise position and is prevented from operatively engaging the teeth on the ratchet 83. These pins 3 may be arranged in any series to provide for any desired combination of movement and idleness throughout the twenty-four-hour period.

From the foregoing it is believed that our invention may be readily understood by those skilled in the art without further description, it being borne in mind. that numerous changes may be made in the details disclosed without departing from the spirit of the invention as set forth in the following claims.

What we claim and desire to secure by Letters Patent is:-

I. The combination with a iiuid controlling valve, a vaive control member, a. train of gears for actuating said member, diaphragm actuated means for operating said train o1" gears, iiuid means for actuating said diaphragm, a spring clock mechanism, means associated therewith lor timing the admission of fluid to said diaphragm, and means actuated by said diaphragm for winding said clock mechanism.

2. In a time controlled valve actuating mechanism, a valve actuating lever, a rotary disc, means carried by said disc selectively engageable by said lever, a fluid actuated diaphragm, a reciprocating rack operated by said diaphragm., a gear in mesh with said rack, a pawl and ratchet mechanism operatively connected to said gear and means operatively connecting said ratchet mechanism and said disc to rotate the latter upon the movement of said rack, and a clock mechanism for timing the operation of said diaphragm.

3. Apparatus as claimed in claim 2 including means controlled by said diaphragm for winding said clock mechanism.

4. Apparatus as claimed in claim 2 including means operatively associated with said pawl and ratchet mechanism for selectively controlling the rotation of said disc.

5. In a time controlled valve actuating mechanism, a valve actuating lever, a rotary disc, means carried by said disc selectively engageable by said lever for periodically actuating said valve lever, a uid actuated power unit for operating said disc, a spring clock mechanism, means operated thereby for timing the admission of uid to said power unit, means actuated by said power unit for winding` said clock mechanism, and means controlled by said clock mechanism for selectively controlling the rotation of said disc.

6. Apparatus as claimed in claim 5 wherein said last named means comprises a second disc interposed between said power unit and said first disc and provided with selective means for controlling the periodic rotation oi said mst named disc.

7. In a time controlled Valve actuating mechanism, a valve actuating member, a fluid operated driving unit, means operatively connecting said unit with said valve actuating member, a control valve for admitting fluid to said driving unit, a spring clock, means actuated thereby for periodically opening and closing said control valve, means controlled by said unit for winding said clock, and means ior periodically preventing operation of said valve actuating member.

8. In a time controlled valve actuating mechanism, a valve actuating member, a fluid operated driving unit, means operatively connecting said unit with said valve actuating member, a control valve for admitting iuid to said driving unit, a spring clock, means actuated thereby for periodically opening and closing said control valve, means controlled by said unit for winding said clock, and means controlled by said clock for periodically preventing operation of said valve actuating member.

9. In a time control mechanism, a rotary control member, a pawl and ratchet mechanism for operating said member, a power unit for operating said pawl, a clock mechanism, means associated therewith for timing the operation of said power unit, means for regulating the pick-up of said pawl with respect to said ratchet, means actuated by said power unit for winding said clock mechanism, and means for periodically rendering said pawl mechanism inoperative Without affecting the continued operation of said power unit and clock mechanism.

10. The combination with a fluid controlling valve, oi a valve actuating member, a fluid operated power unit, means operatively connecting said power unit with said valve actuating member, a spring clock, means actuated by said clock for controlling the operation of said power unit, means controlled by said power unit for winding said clock, comprising a freely rotatable ratchet operatively secured to one end of the main spring of said clock, a timing gear Xed to the other end of said main spring, a pawl member operatively associated with said ratchet, spring means for moving said pawl member in one direction for winding said main spring, means normally tending to force said pawl member in the opposite direction against the tension of said spring means, and means actuated by said power unit for releasing said last named means, whereby said pawl and spring means cause the rotation of said ratchet to wind said main spring.

1l. In mechanism of the class described, a driven element, a iluid operated driving unit therefor, a valve for controlling the admission of fluid tosaid driving unit, a spring clock, means actuated thereby for periodically opening and closing said valve, means controlled by said driving unit for winding said clock, a rotary disc driven by said clock, and means on said disc for selectively controlling the operation of said driven element.

12. In a time control mechanism, a rotary control member, a pawl and ratchet mechanism for operating said member, a spring normally tending to retract said pawl, a power unit, means operated by said power unit for forcing said pawl in the opposite direction against the tension of said spring, a clock mechanism, means associated therewith for timing the operation of said power unit, means. actuated by said power unit for winding said clock mechanism, and means for regulating the pick-up of said pawl with respect to said ratchet.

13. Mechanism as claimed in claim 12 wherein said last named means comprises a rating screw adjustable to vary the retraction of said pawl, whereby the number of teeth on said ratchet picked up by said pawl is determined.

14. In a time control mechanism, a rotary control member, a pawl and ratchet mechanism for operating said member, a spring normally tending to retract said pawl, a power unit, a lever actuated by said power unit for forcing said pawl in the opposite direction against the tension of said spring, a clock mechanism, means associated therewith for timing the operation of said power unit, a disc driven by said clock, selective projections on said disc, and an extension on said lever adapted to engage said selective projections,

whereby the retraction of said pawl by said spring is periodically prevented.

15. In a time controlled valve actuating mechanism, a valve actuating lever, a rotary disc, means carried by said disc selectively engageable by said lever, a fluid actuated diaphragm, a reciprocating post operated by said diaphragm, a pawl and ratchet mechanism, means operatively connecting said ratchet to said disc, means operatively connecting said pawl to said post, a valve for controlling the admission of iiuid to said power unit, a valve actuating stem` carried by said post, a clock mechanism, and means actuated by said clock mechanism for periodically operating said valve stem.

LEON J GRIFFEY. CHESTER C. HERNDON. 

